Rigid balloon catheters have been used to treat nasolacrimal and paranasal sinus obstructions as disclosed in my U.S. Pat. Nos. 7,169,163 and 8,317,816 respectively. Physical obstruction problems occurring in the lacrimal drainage system can be treated using a dual conduit irrigating and suctioning lacrimal catheter, having a dilatation balloon as disclosed in my U.S. Patent Application Publication No. 20090204142, incorporated herein by reference. Such catheters can be used to perform balloon catheter dacryocystoplasty (DCP) and dacryocystorhinostomy (DCR) both translacrimally and transnasally.
The above dual conduit catheter can be formed by a semirigid stainless steel hypotube coaxially penetrating through the sidewall and into the central lumen of a diametrically slightly oversized flexible plastic tube having a reduced thickness distal portion which can inflate as a dilatation or anchoring balloon. The hypotube can be connected at its proximal end to an irrigation or suction supply while the proximal end of the flexible tube can be connected to a compressed fluid balloon inflation supply.
As shown in Gould et al., U.S. Pat. No. 4,572,186, a V-shaped adapter assembly, also known as a hub, can secure the proximal ends of two catheter conduits in a single, hand-graspable structure.
Because a dual conduit catheter can be subjected to relatively large axial forces during insertion through or around obstructions or other barrier structures, unwanted slippage can occur between the various structures such as between a hypotube and portions of the flexible tube and/or hub, thus breaking the catheter and/or making it difficult for the surgeon to properly manipulate and place the catheter in the body. It has been found that axial forces of 10 Newtons run the risk of breaking the above catheter designs.
The instant invention results from attempts to avoid some or all of the above disadvantages.